Hi Muzza, TO goes over DT once dry & cured quite well but never tried mixing it together. Don't think it would work as TO seems more oil based whilst DT seems more watery.

Did an experiment adding colours to TO and it did not like the water based additives as once all shook up the colour seemed to be just small suspended balls in an otherwise oily solution.

Here is an idea....a bit messy but it should do the trick, not cost too much and you may even already have the ingredients in your kitchen. Ever noticed how Indian Curries seem to leave a yellowish stain on things? Tumeric is the main culprit and comes in those cheap little packets in the herbs & spices section at the supermarket. You will need gloves as this stuff stains almost forever, well many days at least before coming off your hands and fingers.

My wife cooks with Tumeric all the time and it leaves stains on the stone kitchen bench tops all the time. Only way to get it off is to apply small amount of undiluted hand dishwashing liquid to the affected area and leave overnight and it simply wipes off next morning.

You could either sprinkle a bit in with a small amount of TO, shake that around for 30 seconds to blend and then apply to scrap bit of wood. If that works without coming out grainy or lumpy maybe try on a bit of scrap plastic of similar composition to the binding to see how it reacts/attaches.

Alternatively create a paste like mixture and spread it thinly on the scrap timber or plastic to see how it turns out. Once dried out (24 hours or more) simply wipe off the excess and allow to dry for another day or so and then lightly apply 1st coat of TO with a brush as ragging will drag the stain just laid down. TO does have a slight amber tint and when combined with Tumeric should give off an aged ivory appearance.

With a delicate stain coat that is followed by TO I have always done initial couple of coats lightly with a brush as the rag method does grab and drag the underlying stain and can create an awful mess. Once a couple of TO's are down and dried out best to revert to ragging otherwise the brush marks become really obvious and therefore require heavy wet sanding to remove.

Good luck buddy and hope you like some of these ideas.